We propose in a study of approximately 1100 post-coronary patients to determine (1) whether modification of various emotional factors comprising Type A behavior can be achieved in a significant fraction of these individuals and (2) whether such modified individuals will exhibit a statistically significant decreased incidence of recurrent myocardial infarction or sudden death. Six hundred of the 900 subjects (the experimental group) will be subject to group therapy designed to modify their Type A behavior and also encouraged to adhere to their usual regimen regarding their heart disease. A second group of 300 subjects only will receive encouragement to adhere to the usually prescribed regimen employed in "between-event" therapy of post-coronary patients. A third group of 200 subjects will serve as pure controls and will only be examined every 18 months.